This green-haired alien girl can rip your clothes off AND make you super-horny with just a strobe-flash of her eyes. Some people think science fiction hentai porn is all about tentacle monsters, but they're dead wrong. There are mad scientists who transform women into super-evolved sex-monsters, androids who need human sperm to upgrade their firmware, and women who ride naked on the shoulders of giant robots. Here's our complete guide to the worlds of science fiction hentai, with no tentacles. And yeah, it's not even remotely work-safe, unless you work on a sex-sphere.For convenience, we've divided the motherlode of hentai clips (and a couple galleries) into four main sub-pages: space pirates, mechas, mad scientists and aliens.